1. Field of the Invention
The present invention relates, generally, to systems and methods for sharing a fleet of vehicles among a plurality of users and, in preferred embodiments, to such systems and methods for sharing a fleet of electric vehicles, including systems and methods relating to allocating, tracking, securing, managing and relocating of shared vehicles and, in yet further preferred embodiments, to systems and methods relating to allocating, tracking, securing, managing, relocating and charging of shared electric vehicles.
2. Description of the Related Art
In most modern, industrial countries, private automobiles play an important and sometimes indispensable role as a means for transporting people within and beyond local areas, for example, to and from places of work, study or worship, on errand trips or in commercial activities, such as deliveries, sales visits, repair visits or the like. As a result of these important roles, the number of automobiles in and around most industrialized cities and neighboring regions continues to grow. The increasing numbers of automobiles results in higher occurrences of traffic jams and higher demands for parking spaces.
Mass transit systems, such as busses, commuter trains, subways, streetcars or the like can fulfill some of the transportation needs of those communities and municipalities that have such systems. However, travel with such systems is confined to pre-set stop locations and times, set by the route and time schedule of the bus, train, subway or streetcar. The prescribed routes and time schedules typically do not meet many travelers' needs or are too inconvenient for practical usage of the mass transportation system by some travelers. For many mass transportation users, the pre-set stop location is far enough from their origination or destination locations that they must find additional modes of transportation to or from the pre-set stop. For example, some users drive private vehicles to and from pre-set stop locations and park the vehicles near the stop locations. Some mass transportation systems even provide vehicle parking facilities near pre-set stop locations for such users.
For example, commuter train stops and bus stops in and near some cites are often provided with parking lots for train users to park private vehicles. However, vehicles in such parking lots typically remain parked throughout a large part of the day, and are driven only in the morning to bring the user to the train or bus stop and in the evening to take from the train or bus stop. Thus, while modem mass transportation systems can result in a reduced number of vehicles on the road at any given time, such mass transportation systems do not eliminate the need for private vehicles and can result in an inefficient use of private vehicles.
Accordingly, there is a need for a system and method for the efficient and convenient use of private vehicles, such as an efficient and convenient shared vehicle system and method. Shared vehicle systems can provide more flexibility than other means of public transportation. In a shared vehicle system, a number of vehicles are normally maintained in several designated parking areas. Each user is allowed to pick up a vehicle at one parking area, and return the vehicle to the parking area nearest to the user's destination. The user may also drive a vehicle out of a designated parking area for an errand and return the vehicle to the same designated parking area. Shared vehicle systems that are used by a relatively large number of subscribers should include sufficient security measures to protect the vehicles from theft and also to protect the user from crime.
Shared vehicle systems must be sufficiently convenient to motivate users to employ the system. Accordingly, vehicle availability within a reasonable time of a user's request for a vehicle is very important to the success of such a system. Of course, by maintaining a greater number of vehicles in the fleet of shared vehicles, the availability of a vehicle at any given time can be increased. However, system cost is minimized and vehicle-usage efficiency is maximized with smaller vehicle fleets. Accordingly, there is a need for a shared vehicle system that maximizes user convenience yet minimizes the number of vehicles required in the fleet.
In particular, by employing vehicles in a shared vehicle system or method, additional ecological advantages can be achieved. Vehicles in a shared system may be of many types. They may be the conventional petroleum based gasoline or diesel fuel type vehicles. They may however be cleaner forms of propulsion such as methanol or propane powered vehicles, or may be vehicles powered by hydrogen stored as a gas or metal hydride. Electric vehicles may draw energy from batteries, fuel cells, generators driven by internal combustion engines, or combinations of different energy sources. Electric vehicles powered by both lead acid and nickel metal hydride batteries have shown much promise and several manufacturers have produced viable electric vehicles employing these battery technologies. Electric vehicles are a good candidate for a shared vehicle, because they are among the cleanest and quietest forms of vehicle, but sharing systems and methods are in no way dependent on the use of an electric vehicle, and may be employed with a number of non electrical or hybrid technologies, including common gasoline power.
The use of electric powered vehicles in a fleet of shared vehicles, however, presents further complexities over other alternate power vehicles, for example, associated with vehicle charging requirements and vehicle unavailability during charging times.
Electric vehicles typically require charging more often than the conventional vehicles require refueling. Recharging stations are not nearly as available as conventional petroleum motor fuels. Moreover, recharging of an electric vehicle typically takes much more time than refueling a conventional vehicle. Thus, if a conventional vehicle is present at a designated parking area of a shared vehicle system, but does not have sufficient fuel to meet a user's travel needs, the vehicle can be quickly refueled and made available to the user. However, even when an electric vehicle is idle in a designated parking space, it is not available to a user unless it has a sufficient existing state of charge (SOC) to make the user's intended trip. Typically, an electric vehicle cannot be re-charged quickly enough to make the intended trip if its existing SOC is inadequate. On the other hand, if the user intends to make a short trip, the vehicle may be capable of making the intended trip even though it is not fully charged. Accordingly, there is a further need for a system and method for managing shared electric vehicles in an optimum fashion and to meet the needs of a maximum number of users with a minimum number of vehicles.